Induction of Strong and Specific Humoral and T-helper 1 Cellular Responses by HBsAg Entrapped in the Methanobrevibacter smithii Archaeosomes

BACKGROUND: Application of adjuvants with microbial origins is a recently highlighted approach in the vaccinology trials. Archaeosomes are among these microbial compounds with both adjuvant and liposomal activities and features. METHODS: In the present study, recombinant HBsAg encapsulated into Methanobrevibacter smithii (M. smithii) archaeosomes. Balb/c mice immunized with this compound and humoral and cytokine secretion pattern of immunized models analyzed. RESULTS: Frequency of IFN-γ secreting cells in the HBsAg-containing archaeosomes group was significantly higher than HBsAg and HBsAg(+)C/IFA groups (p≤0.05). IgG2a titer in the sera of HBsAg-containing archaeosomes group was also significantly higher than this subclass titer in the other groups (p≤ 0.05). CONCLUSION: Analysis of induced responses revealed the immunopotentiating characteristics of M. smithii archaeosomes in the induction of T-helper 1 responses according to the dominance of IgG2a subtype and IFN-γ secreting splenocytes of immunized mice.